import 'package:drift/drift.dart';

import '../Entities/drift_database.dart';
import '../Entities/time_frame_enum.dart';
import '../Repositories/recurring_transacation_repository.dart';
import '../Repositories/transaction_repository.dart';
import 'task.dart';

/// Generiert neue Transaktionen
/// anhand der erstellten wiederkehrenden Transaktionen
class GenerateTransactionsTask extends Task {
  final TransactionRepository _transactionRepository = TransactionRepository();
  final RecurringTransactionRepository _recurringTransactionRepository =
      RecurringTransactionRepository();

  @override
  Future<bool> execute() async {
    final List<RecurringTransaction> recurringTransactions =
        await _recurringTransactionRepository.findBy();

    for (final recurringTransaction in recurringTransactions) {
      final List<Transaction> transactions = await _transactionRepository
          .findBy(
            recurringTransaction: recurringTransaction,
            orderBy: 'dateDesc',
          );
      final Transaction? transaction = transactions.firstOrNull;

      final DateTime date = (transaction != null)
          ? transaction.date!
          : recurringTransaction.startDate!;
      final DateTime nextTransactionDate;

      switch (recurringTransaction.timeFrame) {
        case TimeFrameEnum.daily:
          nextTransactionDate = date.add(const Duration(days: 1));
        case TimeFrameEnum.weekly:
          nextTransactionDate = date.add(const Duration(days: 7));
        case TimeFrameEnum.monthly:
          nextTransactionDate = DateTime(date.year, date.month + 1, date.day);
        case TimeFrameEnum.yearly:
          nextTransactionDate = DateTime(date.year + 1, date.month, date.day);
      }

      if (DateTime.now().compareTo(nextTransactionDate) <= 0) {
        final TransactionsCompanion transaction = TransactionsCompanion(
          name: Value(recurringTransaction.name),
          date: Value(nextTransactionDate),
          amount: Value(recurringTransaction.amount),
          checked: const Value(false),
          accountId: Value(recurringTransaction.accountId),
          recurringTransactionId: Value(recurringTransaction.id),
        );

        await _transactionRepository.add(transaction);
      }
    }

    return true;
  }
}